1. Field of the Invention
This invention relates generally to machinery used in processing of beef, pork, whole chickens and chicken parts, and more particularly to an injection machine utilizing a specific bushing construction which may advantageously be used in machines for injecting various formulations and fluids, including marinade formulations, aqueous liquid solutions which may be corrosive, and for thermally conditioning food products with live steam at sufficiently high temperatures and pressures to insert sufficient thermal energy into the interior of the food product so that end point temperature meets Federal regulations.
2. The Prior Art
The prior art is exemplified by the practices of Stein-DSI, a business of FMC Food Technology. According to products sold to and used by customers of that company, machinery is provided wherein beef, pork, whole chickens, or chicken parts, are carried on a conveyor and are temporarily positioned under a press containing multiple hollow needles which are adapted to selectively receive a processing fluid under pressure. The press is operated to cycle up and down in a vertical path so that the points of the hollow needles penetrate the meat and inject the processing fluid into the interior portions of the meat.
In the current state of the art, the processing fluid is most often a marinade, i.e., a pickling liquid, or aqueous solution, usually of vinegar or wine with oil, herbs, spices etc. selected to steep the meat before cooking.
Such marinating operations are customarily performed on machines and equipment designed to inject liquid marinade which is relatively cool, for example, at or near room, or ambient, temperature. Thus, the machine function of meat penetration is performed with the use of hollow needles which can be reciprocated in a press which includes a manifold utilizing prior art sealing instrumentalities. Such seals can be fully effective only in the range of relatively low operating temperatures normally contemplated in such an operating environment.
However, in order to thermally treat food products with live steam at elevated temperatures and under pressure, such sealing means are completely unacceptable and are subject to failure, thereby rendering the machine ineffective for thermally conditioning purposes.
The present invention contemplates the construction of an injection machine which utilizes a particularly effective combination of piercing needles and manifold parts in conjunction with a specific form of bushing construction performing two principal functions: (1) the bushing adequately supports the needle in its vertical position throughout a wide range of operating conditions, including thermal conditioning with live steam at elevated temperatures and, (2) the bushing supports an effective heat resistant seal to prevent leakage around the needle with which it is associated when used with live steam at elevated temperatures and under pressure.
Further, by virtue of the special constructions, featuring in one form of the invention, the use of bushing parts made of xe2x80x9cPOLYETHERETHERKETONExe2x80x9d (sometimes referred to by an abbreviation PEEK) and xe2x80x9cOxe2x80x9d ring seals made of xe2x80x9cVITON,xe2x80x9d (a registered trademark of DuPont Dow Elastomers L.L.C. for a heat resistant material made of synthetic rubber and rubber compositions) and featuring in another form of the invention, the use of bushing parts made of stainless steel and xe2x80x9cOxe2x80x9d ring seals made of xe2x80x9cTEFLON,xe2x80x9d (a registered trademark of E.I. DuPont De Nemours and Company for a chemical plastic compound with oil, water and stain repellant characteristics), the bushing constructions disclosed herein can be utilized with either conventional aqueous solutions such as marinade, or with corrosive solutions, at their normal usage temperatures, or with live steam at elevated temperatures in the order of about 350 degrees Fahrenheit and at increased pressures ranging from 15 to 55 pounds per square inch.
The structures thus provided allow the injector apparatus to exploit the characteristics of thermally pre-conditioning a food product, such as meat, to insure that the meat is fully cooked when processed in a large scale mass production processing environment. Live steam can be introduced into the manifold and injected with full and proper penetration of the meat so that elevated internal temperatures are achieved to promote full 100% bacterial kill in the final cooked meat product.
The sealing units provided in accordance with this invention are fully reliable with fluids at temperatures lower than the temperature of live steam, whether such fluids constitute gaseous fluids, corrosive solutions, or aqeous formulations such as marinade. Hence, the structures provided are universally applicable to food processing procedures in a wide range of application without necessitating duplication of large and expensive machinery.